This is NOT a ship, this is a cousinly/family promise. So don't get something perverted out of this --

Plot: During Holiday Break at Hogwarts, Regulus ventures to his cousin Bellatrix's house at night to cry that his brother, Sirius won't even visit them for Christmas. Bellatrix makes her baby cousin a promise that He'll be sorry.

Yah. This was done in about twenty minutes. I was listening to one of my HP soundtracks, and one of the songs inspired me. nodnod

Disclaimer: The Blacks and Potters all belong to JK Rowling, although I dearly wish I did own Bellatrix, Regulus and Sirius.

"Belley…" A young voice whimpered. Tear brimmed eyes looked up through shaggy black hair, his face downcast.

The older cousin's face softened as she reached out to draw her baby cousin Regulus Black out of the cold winter's night. One hand braced against the doorframe, as she wrapped a delicate but strong and comforting arm around his shoulders. "Reggy…what happened?" She cooed in a soothing voice, sounding a tad anxious herself.

"He won't even come home for Christmas!" The younger brother of Sirius cried out. Forgetting the proud aristocratic face he was suppose to wear and live by, he threw his arms around the taller girl's waist, burying his face in her chest and breaking down with a sob.

Bellatrix instantly wrapped her arms around his shoulders, stroking his soft black hair that matched her own flowing locks. "Oh Little Prince…" She said softly, the door shutting and leaving the two cousins in the large and empty entrance hall of the Black Manor.

"I hate Potter!" Regulus sobbed, clutching the side of Bellatrix's dark purple gown in his fist. "Sirius won't even come home because of him!"

Glancing over her shoulder for any intruders, the eldest Black sister led her baby cousin to a hardly-used parlor, sinking down with him still cradled in her arms onto a loveseat. "Shhh…" She breathed, rocking him back and fourth as he sobbed into her shoulder, his other hand clutching the sleeve of her upper shoulder.

"He just sneered at me when I asked him Bella! I begged him, and he said that he was with his family, and he wouldn't return home. He's living with those bloody Potters, celebrating Christmas with THEM!" Regulus cried as tears streamed down his pale face. Bellatrix gently stroke them away with her long fingers, gazing down into her cousin's pain filled eyes with her own mournful ones.

"He's never coming home Bella…" Regulus struggled to gasp, the sobs subsiding to silent tears strolling down his young 4th year face. "And it's all Potter's fault!"

"Oh baby cousin…" Bellatrix crooned, lightly running her slender hands down his cheek. "It's true. That bloody Potter stole your brother." The ever cunning, manipulating and sly Bellatrix Black did take sincere sympathy with Regulus. She herself had shed tears, and begged her father to let her go after Sirius and find him when a few months earlier, he had ran away from home during the summer. But when school had started, her pain had turned to loath when she learned he was staying with the Potter Family.

And to further the hatred of that family in Regulus's mine, Bellatrix blamed everything she could about Sirius on James Potter. "Sirius betrayed you, Reggy." She purred in her gentlest voice. "He left you for Potter. He thinks as Potter as a brother…not you."

There was another hurt sob, but the fists on her side and shoulder tightened. "I hate him..." growled a tearful voice, muffled against her chest. The black-haired head slowly raised, and Regulus growled again, "I hate him…I'll kill him! He took my brother away!"

"Good…" Bellatrix praised in a crooning voice, pushing his floppy black hair out of his face. Wiping at the tearstains on his cheeks, she smiled at him, her eyes narrowed as she gazed at him.

"I will make him sorry, baby cousin. I will make them both sorry. Potter will suffer…and Sirius will regret he ever became friends with that boy."

The youngest Black looked up at his cousin, wiping his nose as he fell against her. "Really Belley…" He breathed with a shudder, still clutching her.

"I promise." She purred, closing her eyes and kissing his forehead. "I promise I will kill him."